Absolutely terrible developers exist, some have 5, 10, or 20 years of experience. I have worked with at least two of them in my career. One was a co worker at a startup. He seemed smart and confident but he just didn't do any work and focused on things like "optimizing code linting" and breaking our DNS, telling us it was fixed then laughing at us while we had to wait 24 hours for the new fixed DNS stuff to resolve. Due to a comedy of errors by our companies management, he was able to last 12 months and was fired on vesting day. More recently at a different company, we hired a guy with 4 years of tech consulting and free lancing experience and he nearly destroyed the company twice in two months and I then fired him. He did surprisingly well on our interview that we designed to be less crappy than the general tech interview loop, but in retrospect his success was clearly a sign that our interview loop was extremely broken. Having "false negatives" isn't great, but having a single false positive can literally destroy your company. People with multiple years of experience just may be the crappy developer that destroys your startup.